Method s Among 274 families ,808 individuals were surveyed by stratified-clu ster random sampling in the rural area in Wudang town, and an ananlysis was perf ormed about the health status of rural families.

 
  • 方法 :采用分層整群隨機抽樣方法 ,對武當山鎮 2 74戶(hù)家庭共 80 8個(gè)農村居民進(jìn)行了家庭健康的抽樣調查。
今日熱詞
目錄 附錄 查詞歷史
国内精品美女A∨在线播放xuan